Methods of compression embossing fibrous webs are known in the art. Methods of heat embossing fibrous webs including fibrous webs comprising thermoplastic fibers are also known. In general, the heat embossing is done by means of heated rollers, with the fibrous web traveling through the nip between the counterrotating heated rollers. To maintain a good through-put speed, the rollers are usually heated a few degrees higher than the melting point of the thermoplastic fibers in the web or the temperature desired in the embossing process. This is necessary so that the web traveling quickly through the nip achieves the desired temperature.
Fabrics which have been heat embossed and in particular fabrics which have been heat embossed in a pattern by patterned rollers often display damage from excessive heat. In particular, in order to achieve heat sufficient to fuse the fibers in the patterned regions, the fibers immediately adjacent the patterned regions are heated to a temperature sufficient to cause shrinkage and damage. The heat radiated to the fibers next adjacent the patterned area also shrinks the web blurring the line of demarkation of the pattern. In the method of the present invention, a combination of heat and pressure is used to compact the fibers in the patterned regions in the web. This combination of factors does not effectively radiate to the fibers next adjacent the pattern region of the fabric, creating a fabric with very sharp pattern delineation and high loft adjacent the pattern region.
It is also old in the art to cold emboss to form or laminate fibrous layers. Cold embossing of moist fibrous layer produces a compacted product which exhibits deformation of fibers and hydrogen bonding. Paper toweling is often made by such a method. The compaction achieved with cold embossing can be undone with water. In the method and fabric of the present invention, the compaction of the fibrous web may not be reversed or undone by the application of water.